Wanna get money back but have some problems

Hello, I have problem with my avast account.
I have no access to that pc where avast product was bought, because I have new one and I forget to cancel automatic renewal and I got a message from my bank that this product was bought. My sister has an access to this pc. But this license has no @mail so I didn’t get a message with product id or order id(you know). What can I do to get my money back?

Orders, Renewals, and Refunds - FAQs >> https://support.avast.com/en-eu/article/Order-Renew-Refund-FAQ

It won’t help because I have no messages on my email.

Contact Sales: https://support.avast.com/en-us/contact/enter/